European photopatch test baseline series: A 3-year experience

Background: In 2012, a consensus was reached regarding a baseline photopatch test series on the basis of the results of a European multicentre study. Objectives: To describe experience with the European photopatch test series. Methods: A retrospective analysis of 116 patients tested with the European photopatch test series between 2014 and 2016 was performed. Results: Fifty-five positive photopatch test reactions in 25 subjects were recorded, most commonly caused by the topical non-steroidal anti-inflammatory drugs ketoprofen, dexketoprofen, and etofenomate. Organic ultraviolet (UV) absorbers constituted the second main category of agents eliciting positive photopatch test reactions. Among UV absorbers, benozophenone-3 and octocrylene were the most frequent photoallergens. UV absorbers that have been introduced more recently rarely elicited positive photopatch test reactions. Positive patch test reactions were less commonly observed than positive photopatch test reactions, namely, 21 reactions in 14 patients. Conclusions: We present the largest clinical experience with the European photopatch test baseline series hitherto reported. The results are similar to those underlying the above consensus process, reaffirming the usefulness of this series.